The Pirc Defence, sometimes known as the Ufimtsev Defence, is a chess opening characterised by Black responding to 1. e4 with 1. ...d6 and 2. ...Nf6 (see algebraic notation) and allowing White to establish an impressive-looking centre with pawns on d4 and e4. It is named after the Yugoslav GrandmasterVasja Pirc.

The Pirc Defence is a relatively new opening. In the 1930s it was considered inferior, but by the 1960s it was found to be quite playable. This opening is tricky to play and correct play of it may be counter-intuitive. Black does not aim for immediate center control, but rather to undermine White´s center.

Move order is not so critical in the Pirc as in other openings, but a typical sequence might be 1.e4 d6 2.d4 Nf6 3.Nc3 g6, with Black fianchettoing his bishop on g7 next move. A distinction is sometimes drawn between the Pirc and lines where Black delays the development of his knight to f6 — this is known as the Modern Defence.

White may adopt a variety of setups to counter those of Black. In placing pawns on d4, e4 and f4, he may establish a large centre, with plans to push in the centre and possibly attack on the king-side (this is the Austrian Attack); Black often counters with ...c5 to break the pawn centre up. A more modest plan for White is to not move his f-pawn and simply use his central pawns to cramp Black. Other approaches are to play f3 to bolster the centre or to fianchetto the king´s bishop with g3 and Bg2. If Black delays ...Nf6, White may play c4 before Nc3, in which case the game might transpose to the King´s Indian Defence.

A rarely seen early deviation by Black is 1.e4 d6 2.d4 Nf6 3.Nc3 e5, which Zurab Azmaiparashvili has tried a few times. This can lead to unique lines after 4.dxe5, or can transpose to the Philidor Defence after 4.Nf3.